It's an upper made by dtech. My brother has a 25 dti and it is amazing. I would also opt for the 6mm if I was you. Especially for deer. Hard time finding a good deer bullet in 25 cal in the 80 90 gr. Plenty in that range in 6 mm.
Pm me if you would like me to. He has taken a few yotes and a very large doe. Pig hunt coming in two weeks.